Vehicle suspension control with actuating circuit protection

摘要

A motor vehicle suspension control includes a solenoid actuator having an actuating coil connected in series with a transistor across an electric power source and circuit protection apparatus for the transistor. The voltage across the transistor is monitored, after a short time delay following turn-on, as a signal indicative of excessive current therethrough. If the signal so indicates, the transistor is turned off for a period of time and then turned on again for another try. This continues for a predetermined maximum number of attempts. Specific clocked digital circuitry is disclosed for controlling the operation and producing the different required time delays or counts.